Name: Lac Operon
Uploaded: 2019-07-19
Duration: 9 min 11 s
Description: A lac operon is a group of genes with a single promoter The genes in the operon encode proteins that allow the bacteria to use lactose as an energy source. L...

Question

Describe in brief the initiation phase of transcription.

Accepted Answer

To begin transcribing a gene, RNA polymerase binds to the DNA of the gene at a region called the promoter. The promoter tells the polymerase enzyme that from where it should begin transcription.

The promoter region contains recognition sites for RNA polymerase to which it can bind. The σ (sigma) factor of RNA polymerase recognises the promoter sequence in the double helix DNA. The double-stranded DNA unwinds in the promoter region so that RNA polymerase can begin transcription.

Each gene has its own promoter. A promoter contains DNA sequences that let RNA polymerase attach to the DNA. Once the transcription bubble has formed, the polymerase can start transcribing.

Describe in brief the initiation phase of transcription.

Important Questions on Molecular Basis of Inheritance

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